// Field validation
    // ----------------------------------------------------------------------

    /**
     * Asserts:
     * <p/>
     * <ul>
     * <li><code>string.length == null</code>
     * <li><code>string.length == 0</code>
     * </ul>
     */
    private static boolean validateStringEmpty(
            List<BuilderProblem> problems, String fieldName, String string, String message) {

 *
 * <p>This pattern ensures the following:
 *
 * <ul>
 *   <li>Each {@code Closeable} resource that is successfully registered will be closed later.
 *   <li>If a {@code Throwable} is thrown in the try block, no exceptions that occur when attempting
 *       to close resources will be thrown from the finally block. The throwable from the try block
 *       will be thrown.

 *   <li>Convert multiple instances "forward" using {@code converter.convertAll(as)}.
 *   <li>Convert in the "backward" direction using {@code converter.reverse().convert(b)} or {@code
 *       converter.reverse().convertAll(bs)}.
 *   <li>Use {@code converter} or {@code converter.reverse()} anywhere a {@link
 *       java.util.function.Function} is accepted (for example {@link java.util.stream.Stream#map
 *       Stream.map}).

		stsOpts.DurationSeconds = int(expiryDuration.Seconds())
	}
	li, err := cr.NewSTSAssumeRole(stsEndpoint, stsOpts)
	if err != nil {
		log.Fatalf("Error initializing STS Identity: %v", err)
	}

	stsEndpointURL, err := url.Parse(stsEndpoint)
	if err != nil {
		log.Fatalf("Error parsing sts endpoint: %v", err)
	}

	opts := &minio.Options{
		Creds:  li,
		Secure: stsEndpointURL.Scheme == "https",
	}

 *
 * <p>The following types of methods are provided:
 *
 * <ul>
 *   <li>chaining methods which return a new {@code FluentIterable} based in some way on the
 *       contents of the current one (for example {@link #transform})
 *   <li>element extraction methods which facilitate the retrieval of certain elements (for example
 *       {@link #last})
 *   <li>query methods which answer questions about the {@code FluentIterable}'s contents (for

 *
 * <p>Some uses of this class include
 *
 * <ul>
 *   <li>As a method return type, as an alternative to returning {@code null} to indicate that no
 *       value was available
 *   <li>To distinguish between "unknown" (for example, not present in a map) and "known to have no
 *       value" (present in the map, with value {@code Optional.absent()})

</p>
<ul>
	<li>its kind, indicating whether it is an ordinary data read, an ordinary data write,
    or a <i>synchronizing operation</i> such as an atomic data access,
	a mutex operation, or a channel operation,</li>
	<li>its location in the program,</li>
	<li>the memory location or variable being accessed, and</li>
	<li>the values read or written by the operation.</li>
</ul>
<p>

 *
 * <ol>
 *   <li>A pipeline starts at its leaf step (or steps), which is created from either a callable
 *       block or a {@link ListenableFuture}.
 *   <li>Each other step is derived from one or more input steps. At each step, zero or more objects
 *       can be captured for later closing.
 *   <li>There is one last step (the root of the tree), from which you can extract the final result

   * The hashtable object. This can be either:
   *
   * <ul>
   *   <li>a byte[], short[], or int[], with size a power of two, created by
   *       CompactHashing.createTable, whose values are either
   *       <ul>
   *         <li>UNSET, meaning "null pointer"
   *         <li>one plus an index into the entries and elements array
   *       </ul>

   *
   * <ul>
   *   <li>{@code null} initial state, nothing has happened.
   *   <li>{@link Cancellation} terminal state, {@code cancel} was called.
   *   <li>{@link Failure} terminal state, {@code setException} was called.
   *   <li>{@link SetFuture} intermediate state, {@code setFuture} was called.
   *   <li>{@link #NULL} terminal state, {@code set(null)} was called.